Pressure-regulating system



April 28, 1931., G. c. LAMMERT PRESSURE REGULTING SYSTEM Filed June 23. 1928 fla Il @lime/" @www FFC GEORGE C. LAMMERT, OF CHICAGO, ILLINOIS PRESSURE-REGULATING SYSTEM Application filed June 23, 1928. Serial No. 287,708.

My invention relates to pressure regulatconnection between the cylinder and atmosing systems and has to do more particularly phere may be provided so that part of the air With air or gas pressure systems in Which taken into the cylinder Will be exhausted the air or gas vpressure in a supply line or during the compression stroke befoie cointank is to be maintained at substantially a pression of the remaining air takes place so ab constant pressure. that the amount of air delivered by the cylin n systems Where an air or gas pressure is der is reduced below its normal capacity. used, suoli as for oil burning or other purrl`hus With the pump ruiming at constant poses, a pump is usually supplied having a speed, by varying this auxiliary opening the capacity to maintain the pressure at a subamount of air delivered by the compressor G0 stantially constant rate With a predetermay be varied and to a certain degree the mined substantial constant consumption of pressure in the delivery or consumption-line the air. Insuch systems there is frequently be maintained at a substantially constant a variation in consumption and with the pressure. It has been found, however, that pump running at a constant speed the line' the amount of air Which a cylinder may be pressure Will vary with the consumption. relieved of in this manner is limited to some Such variation is frequently undesirable, ext/cnt, dependingion how early the exhaust particularly Where a substantially constant port opens before the compression stroke is pressure is most effective. Such variations completed. lt frequently happens that alof line pressure With variations in consumpthough the cylinder is thus relieved to its 'I0 tion occur more particularly Where rotary fullest extent, it is still insufhcient to keep valveless compressors are used in Which there, the pressure in tlie'supply line down to the is a constant intake and constant output with desired point. K constant speed of the compressor. To overcome this last difficulty l have pro- To overcome this variation in consumpvided a control in my improved valve, Wheretion-line pressure, l have provided a system by this auxiliary exhaust port or opening of control including a novel form of valve may be varied up to thefullest capacity of Which is connected to the pump cylinder and relief of the cylinder, but should this be iiiexhaust or delivery line, or to `the consumpsuiilcieiit to maintain the line pressure contion-line or chamber, as the case may be, so etant, the valve is further operated or con-` 80 that a variation or increase in pressure of trolled so as to relieve the line of pressure the delivery line Will operate the valve to in excess of What the auxiliary port can vary the amount of air that is compressed take care of and thus maintains substanby the pump cylinder and thus vary the tially constant line pressure. amount of air delivered by the pump and Foy a bei-,ter understanding of my nven- S5 hooby monlan 9# Substantially Consta@ tion reference is to be had to the accompanylo@ Prossufo although the amouno of all" ing drawing, in Which l have shown a control taken from the delivery line varies. A System including a rotary pump by Way of further feature of my control system is that iustrton and 'm Which 4U h?. Valveldsn SO Construcid as. im fflhve the Fig. 1 is a side view of a rotary pump With fjevlve? u or cnsum) lnflcu Q- mes* the valve and control connections shown in jlrgsv Eilfo Sloullg dottedelines and With the cylinder head re- J A P l J` moved to show the piston construction;

livery line take on a pressure beyond that T. which the `relief of the cylinder alone can *l 1g' 21S an enlarged Vertlcal Sectlonal new 95 through the valve;

rake care of. .1 l f l 1 ln this connection it is to be noted that Fl- 3 19a ft-ht Sco e @Vallon 0 me Va Ve in a rotary pump, for instance, Where an air 0f Fig- 2; With a Portion of the Cylinder head;

inlet is provided for the cylinder,`it has and heretofore been suggested that an auxiliary Fig. 4 is a sectional view through part of 100 the valve showing the valve in its fully opened position. Although the system of my invention may be applied to various kinds of air or gas pressure apparatus, l have illustrated it as used with a val I7eless rotary compressor and Fig. 1 of the drawings illustrates the manner in which the system is arranged.

rlhe comp "essor comprises in general a cast body 10, finished with a central bore 11, with a rotor 12 on a shaft 13 placed eccentric to tie main bore of the pump. Vanes 14 are separated by push rods, connected to the rotor and are automatically adjustable so that the outside or" trie vanes is maintainedin contact with the inside surface of the bore throughout the ent e rotation thereof. An intake line'17 is connected through to the inside or" the bore tlwough port 18, while an exhaust or deliifery line 19 is opened to the bore at 21. As the rotor revolves in the direction indicated by the arrow, a quantity of air or gas is drawn into the continuously expanding space between the vanes 14a and 142) until the vane 14a passes the port 18 at which time the next pair of vanes is read*v to start the same suction operation. At the same time the air between the vanes 14o and 14d is being compressed as the space between them diminishes so as to discharge a quantity of compressed air through the delivery pipe 19. rlhe air between the vanes 14.7) and 140 is also partially compresserhso that the air between any pair oil vanes is gradually compressed and then discharged. he three chambers which are referred to for convenience of description, may be called intake, pressure and discharge chambers, respectively.

rlhe air or O'as tran Jed between the vanesy CD l 14.7) and 14o may be allowed to escape partially through a suitable vent 15 in order to modify the pressure obtained in the line 19. This vent is placed7 however, in such a position that the air in the delivery line cannot pass back through the pressure or discharge chamber and pass out to the atmosphere-or into the compressor illustrated. It is placed 90D in advance of the lower lip of the discharge port and one vane always separates this vent from the delivery opening thus preventing the loss of any high pressure air or gas and its work of compression from the delivery line until the limitations of the pump require it. As pointed out, however, the sim-` Ale venting of this space is. not an entirely practical control expedient and my invention contemplates an improvement in the practice whereby the pressure is more accurately controlled.

Before referring to the system, I shall describe my improved valve designed to make the svstem opera. le and which valve is of particular advantage when used therewith. The valve includes a body 22, the center part of which comprises a cylinder in which a leather washer type of piston 23 is reciprocable. The piston is secured intermediate the ends of a hollow piston rod 24, at one end of which a valve 28 is secured bearing against a seat formed between the cylinder and a chamber 27. Above the piston 23 is a boss 28 through which an opening 29 is provided, a pipe 31 being connected in the opening and adapted to lead to the pressure line 19. Below the piston, a boss has connected thereto a pipe 33 leadingto the intake line 17 in a manner and for a purpose which will be described.

Aiis appears plain from Fig. 2, the pressure in the line 19 being communicated by means et the pipe 31 to the top of the piston 23, such pressure will naturally have the effect of exerting itselt1 against the piston, with the etl'ect of driving said piston downwardly and unseating the valve 26. l have balanced this eii'ect by means or a spring, the tension of which can be adjusted so that the amount of pressure required to displace the piston may be controlled.

ln arranging this spring construction, a rod 34 extending through the valve 26 for the purpose of securing it to the piston rod, extends upwardly into a cylindrical housing 36, which is screwed into a cylindrical portion of the body 22. rlhe upper end of the rod 34 has a sleeve 3'." on which is a spring cap 38 engaging the upper end of a spring 39, the lower end of the spring fitting into a spring support and piston rod guide 41, an annular recess 42 serving to receive the bottoni of the spring and a boss 43 serving as a guide to the upper end of the oiston rod 34.

Lock nuts 46 and 47 are threaded on the sleeve above the spring cap 38 and by means of them, the position of the spring cap is adjusted. A pin 48 prevents the od 34 from turning inside the sleeve 37 and a pair of nuts 49 and 51 serves to secure the upper end of the rod. A washer 52 also acts as a stop for the lock nut 47.

The boss 43 is provided with a number of apertures 56 which lead into the chamber space above the piston 23 so that if the piston rod descends downwardly a sutcient distance, these ports will be uncovered thereby allowing pressure from the line V31, which is the pressure actuating the piston 23, to escape through the ports or apertures 56 down through .the hollow piston rod, and out through ports 57 provided in the lower portion of the rod, whence the pressure escapes throughthe pipe 33 back to the supply pipe of theV pump.

The chamber 27 is provided with a vent 58 which when the valve is secured to the side of the pump with lag screws 59, for example. as shown in F ig. 2, the vent 58 may be opened to the space between the vanes 145 and 140. In other words, the space between the vents in the position which these vanes occupy in Fig. 1, will be open to the vent 58. After sey llfll the valve 26 is closed, the chamber 27 will be air-aight and there will be no loss of pressure. YVhen the valve is open, however, the loss of air through the vent 58 will be in proportion to the amount of openino'.

The bottom of the chamber 27 is apertured to facilitate assembly of the-valve but it is closed by a plug 61. A cap 62 on the top of the spring housing 36 closes the valve off at the top. in connecting the valve into the system, the pipe 31 leads to the pressure line 19, while the pipe 33 leads to the suction or intake line 17. The regulation valve is secured directly on the end of the pump so that the vent 5S may be opened between the vanes 1li?) and idc in the manner previously described.

lin the operation of the device, the tension of the spring 39 is regulated so that it will stand all pressure up to the capacity line of 19, or all that it is desired to-maintain therein. As soon as the pressure exceeds the predetermined amount, the valve 26 will be partly opened and the space between the vanes 140 and 14d will become vented, thus removing a certain amount of air or gas therefrom so that there will be less air or gas compressed in the pressure space between the vanes 140 and 14d and accordingly the presy sure in the line 19 will be decreased.

lf the pressure in the line 19, for some unusual reason, continues to increase, the piston 23 will be driven downwardly carrying the piston rod 24 with it, and still further opening the valve 26. Accordingly, the venting will. continue to be more effective up to a certain point, which as previously described, is determined by the location of the exhaust port. Wlhen this point is reached, if the pressure still increases, the ports 56 will begin to' be uncovered, thus actually opening the line 31 something after the manner of a relief or blow-off valve, and the remaining air delivered by the pump can be sent back to the inlet and it will be impossible for the pressure to increase. The amount of compressed air escaping through the ports 5G is of course determined by the area of such ports uncovered, and the area uncovered will depend on the increase in pressure. I design my valve so that with the entire shutting off of the pipe 19 the pressure generated by the pump can dissipate and there is no possibility of injury either to the line or pump or any apparatus driven or controlled thereby.

Although the description of the opera.- tion of the pump refers to change of pressure in the line 19, it is obvious that these. changes take place with such great rapidity that the effect of the valve is to keep the pressure constant. In other words, the change of pressure will be effective against the valve itself before it will make itself apparent in the place of location of apparatus, for example, oil burners, using the compressed air. The valve and system employing it are therefore efcient to maintam uniform pressure under all conditions from that in which the full capacity of the pump is being utilized by the apparatus, to f that in which substantially all of the apparatus is shut down.

TWhere air is mentioned in the appended claims it is meant to include any compressible gas, afluidrwhich maybe handled by the compressor mechanism described.

Although l have described certain of the features of my invention in order to venable those skilled in the art to practice the same, it is obvious that am not restricted to such details, and the invention is limited only by the scope of the appended claims.

lVhat I claim as new and desire to secure by Unitedv States Letters Patent is 1. A valve mechanism for use in combination with `an air pressure pump having a pressure cylinder and a discharge line comprising means for venting said cylinder during a portion of its cycle of operation when the line pressure increases a predetermined amount, and means for venting said discharge line when the line pressure reaches a still greater amount.

2. Avalve mechanism for use in combination with a rotary air pressure pump having a pressure cylinder and a discharge line comprising means for automatically regulating the output of said cylinder in accordance with the pressure in said discharge line up to a certain pressure, and means for venting the discharge line whenr a still greater pressure exists therein.

3. A valve mechanism for use in combination with an air pressure pump having Aa pressure cylinder and a discharge line comprising means Afor venting the cylinder to the point' at which the exhaust port of the kcylinder opens, and lmeans for venting the renainder of the air from the discharge line up to a point including the entire outputof the pump.

Ll. Avalvemechanism for use in combination with an air pressure pump operating at a constant speed, comprising means for maintainpump independent of the amount of air used from the discharge line within the capacity of the pump, said pump consuming power in accordance with the amount of air delivered.

5. A valve mechanism for use in a valveless rotary compressor having a plurality of vanes, pressure and discharge chambers between the vanes and with intake and discharge lines connected into the intake and discharge chambers, comprising means for venting the pressure chamber up to the point at which it opens to the exhaust port in accordance with the pressure in the discharge line, and means for venting the discharge line in accordance with the pressure therein,

ing a constant pressure discharge from said and when such pressure exceeds a predetermined amount.

6. valve mechanism for use in combina.- tion with a` pressure pump having a pressure cylinder, comprising a valve including a cylinder with a piston therein, a connection from the pressure side of the pump to the piston to operate the valve and means permitting` the escape of some of the air actuating said piston when said piston is advanced a predetermined pressure chamber and said intake line, andl means whereby the i'irst mentioned valve only is actuated up to a predetermined amount, with the second mentioned valve operating thereafter.

9 fr valve mechanism for the purpose described comprising a venting chamber', a chamber connected into an air intake line, a chamber connected into an air pressure line, a valve etween theventing chamber and the intake chamber, a second valve between the pressure chamber and said intake line, and a piston operatedY by the pressure in said pressure line for controlling the operation of both ofsaid valves.

l0. A valve mechanism Jfor the purpose described comprising` a venting chamber, a chamber connected into an air intake line, a chamber connected into air pressure line, a valve between the venting chamber and the intake chamber, a second valve betweenv the pressure chamber and saidl intake line, a piston operated by the pressure in said pressure line for controlling the operation of both oic said valves, and an adjustable pressure spring for predetermining the amount of pressure required to actuate said valve.

11. In a rotary pump having an air compression chamber connected to an output line and provided with a venting aperture, a valve for Vsaid aperture, means for operating said valve in response to pressure in the output line, and means eifective upon a predetermined movement of said valve for venting the line pressure. A

12. In a rotary pump having an air compression chamber connected to an output line and wherein the airis compressed prior to the establishmentY of connection with the output line, said compression chamber having a venting aperture, a valve for controlling the outlet through said aperturesaidvalve being operableV ink response. to line pressure, and means responsive to a predetermined movementor said valve for relieving line pressure. In witness whereof, I hereunto subscribe my name this 21st dayI of J une, 1928.

GEORGE C. LAMMERT. 

